The invention relates to a millimeter wave radar anticollision detection apparatus. A waveform generation module generates a waveform modulation voltage and outputs to a millimeter wave transceiver assembly. The millimeter wave transceiver assembly generates a millimeter wave frequency band emission waveform which is radiated through an antenna and simultaneously receives an object reflection echo through the antenna. After the echo passes through the millimeter wave transceiver assembly, down-conversion is performed and an intermediate frequency beat signal is output. An intermediate frequency pretreatment module carries out automatic gain control to the intermediate frequency beat signal and outputs the signal which is sampled and analyzed by a system control module to a display alarm module. A temperature control module carries out temperature monitoring to the apparatus and forms bidirectional communication with the system control module. The system control module carries out communication and alarm with the outside world through the display alarm module. The apparatus possesses functions of distance measurement, velocity measurement and multi-target identification. The apparatus can adapt various kinds of ground clutters, a bad weather condition and a lot of dust interference on an industry scene. The apparatus can be widely used in various kinds of complex industry scenes and an automobile driving safety field.